Nozzle, and substrate processing apparatus

ABSTRACT

A nozzle for discharging droplets of a processing liquid for processing a substrate has a main body including a supply port, a drain port, a processing liquid flow passageway connecting the supply port and the drain port, and a plurality of discharge ports from which the processing liquid is discharged. The processing liquid flow passageway includes a plurality of branch flow channels, which branch out between the supply port and the drain port and collect together between the supply port and the drain port. The plurality of discharge ports form a plurality of columns respectively corresponding to the plurality of branch flow channels; and are aligned along and connected to the corresponding branch flow channels. A piezo element applies vibration to the processing liquid flowing through the plurality of branch flow channels.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a nozzle that discharges droplets of aprocessing liquid for processing substrate, a substrate processingapparatus that includes the nozzle, and a substrate processing methodthat uses the nozzle. Examples of substrates to be processed includesemiconductor wafers, substrates for liquid crystal displays, substratesfor plasma displays, substrates for FEDs (Field Emission Displays),substrates for optical disks, substrates for magnetic disks, substratesfor magneto-optical disks, substrates for photomasks, ceramicsubstrates, substrates for solar cells, etc.

2. Description of Related Art

In a production process of a semiconductor device or a liquid crystaldisplay device, etc., a cleaning process is performed to removeparticles and other foreign substances from a substrate, such as asemiconductor wafer, a glass substrate for liquid crystal displaydevice, etc. For example, each of Japanese Unexamined Patent ApplicationPublication No. 2007-227878 and Japanese Unexamined Patent ApplicationPublication No. 2010-56376 discloses a substrate processing apparatus ofthe single-substrate treatment type that cleans a substrate by makingdroplets of a processing liquid collide against the substrate.

The substrate processing apparatus described in Japanese UnexaminedPatent Application Publication No. 2007-227878 includes a two-fluidnozzle that forms droplets of a processing liquid by making theprocessing liquid collide with a gas. The two-fluid nozzle includes acasing in which a processing liquid discharge port and a gas dischargeport are formed. When the processing liquid and the gas are dischargedat the same time from the processing liquid discharge port and the gasdischarge port, respectively, the processing liquid and the gas collidein a vicinity of the casing, and droplets of the processing liquid arethereby formed.

The substrate processing apparatus described in Japanese UnexaminedPatent Application Publication No. 2010-56376 includes a cleaning nozzlethat forms droplets of the processing liquid by applying vibration tothe processing liquid. The cleaning nozzle includes a tubular bodyhaving a plurality of discharge ports formed therein and a piezo elementmounted to the tubular body. The processing liquid is supplied at apressure of no more than 10 MPa to an interior of the tubular body. Whenan AC voltage is applied to the piezo element, vibration is applied tothe processing liquid inside the tubular body and droplets of theprocessing liquid are sprayed from the plurality of discharge ports.

In cleaning a substrate by making droplets of a processing liquidcollide against the substrate, it is preferable for a large number ofthe droplets to be sprayed from a nozzle. That is, the greater a numberof times of collision of droplets against the substrate, the higher aprobability of collision against foreign substances attached to thesubstrate and the higher a removal effect, and satisfactory cleaning canthus be performed when the number of droplets sprayed from the nozzle islarge. Further, with a larger number of droplets, the same cleaningprocess can be performed in a shorter time and thus a number ofsubstrates processed per time can be increased. Also, in cleaning asubstrate by making droplets of the processing liquid collide againstthe substrate, it is preferable for a variation in size (particlediameter) of droplets and a variation in speed of the droplets to besmall. That is, when the variation in particle diameter and/or thevariation in speed are or is large, non-uniformity of cleaning may occuror a device pattern formed on the substrate may become damaged and thedevice pattern may become destroyed.

With the two-fluid nozzle described above, the droplets of theprocessing liquid are formed by making the processing liquid and the gascollide. It is thus difficult to control the particle diameter and thespeed. On the other hand, with the cleaning nozzle described in JapaneseUnexamined Patent Application Publication No. 2010-56376, the variationof particle diameter and the variation of speed can be suppressed bycontrolling the pressure of the processing liquid supplied to thecleaning nozzle and the vibration of the piezo element. Satisfactorycleaning can thus be performed.

However, with the cleaning nozzle described in Japanese UnexaminedPatent Application Publication No. 2010-56376, a high pressure isrequired to spray droplets of high speed from small holes and thus theprocessing liquid is supplied to the interior of the tubular body at apressure of 10 MPa at the maximum. Thus, for example, a tubular bodywith adequate thickness must be used to secure strength enablingwithstanding of the liquid pressure in the cleaning nozzle. However, ifthe thickness of the tubular body is large, the cleaning nozzle is madelarge. The cleaning nozzle is installed in a limited space inside thesubstrate processing apparatus and is thus preferably compact.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a nozzle that enablessuppression of variation in size and speed of droplets of a processingliquid sprayed from the nozzle and can suppress enlargement of thenozzle, and to provide a substrate processing apparatus that includesthe nozzle and a substrate processing method using such a nozzle.

Another object of the present invention is to provide a substrateprocessing apparatus and a substrate processing method that enables anentire surface of a substrate to be cleaned adequately.

The present invention provides a nozzle that includes a main body and apiezo element and discharges droplets of a processing liquid forprocessing a substrate. The main body includes a supply port suppliedwith the processing liquid, a drain port from which the processingliquid supplied to the supply port is drained, a processing liquid flowpassageway connecting the supply port and the drain port, and aplurality of discharge ports from which the processing liquid isdischarged. The processing liquid flow passageway includes a pluralityof branch flow channels. The plurality of branch flow channels branchout between the supply port and the drain port and collect togetherbetween the supply port and the drain port. The plurality of dischargeports form a plurality of columns respectively corresponding to theplurality of branch flow channels. Further, the plurality of dischargeports are aligned along the corresponding branch flow channels and areconnected to the corresponding branch flow channels. The piezo elementapplies vibration to the processing liquid flowing through the pluralityof branch flow channels.

With the nozzle of the present arrangement, the processing liquidsupplied to the supply port flows toward the drain port through theprocessing liquid flow passageway. The processing liquid flow passagewayincludes the plurality of branch flow channels. The processing liquidsupplied to the branch flow channels is discharged from the plurality ofdischarge ports connected to the branch flow channels. The processingliquid discharged from the discharge port is disrupted by the vibrationapplied by the piezo element. A plurality of droplets of the processingliquid are thereby sprayed from the nozzle. Further, by the processingliquid supplied to the supply port being drained from the drain port,the processing liquid supplied to the processing liquid flow passagewaycan be suppressed or prevented reliably from being retained in theprocessing liquid flow passageway. Size and speed of the droplets of theprocessing liquid discharged from the discharge ports are controlled,for example, by pressure of the processing liquid supplied to the nozzleand vibration of the piezo element. The variation in size and speed ofthe droplets can thus be suppressed.

As mentioned above, the processing liquid flow passageway includes theplurality of branch flow channels. By branching of the processing liquidflow passageway, the processing liquid flow passageway can be increasedin total length. A larger number of discharge ports can thereby beconnected individually to the processing liquid flow passageway. Alarger number of droplets can thereby be sprayed at the same time fromthe nozzle. For example, connecting of a larger number of dischargeports individually to the processing liquid flow passageway byincreasing a flow path area (area of a cross section orthogonal to theprocessing liquid flow passageway) of the processing liquid flowpassageway may be considered. However, if the flow path area of theprocessing liquid flow passageway increases, a force applied to the mainbody by the pressure of the processing liquid increases. The main bodymust thus be increased in strength, and the nozzle is thereby madelarge. Enlargement of the nozzle can thus be suppressed by branching theprocessing liquid flow passageway. Further, the plurality of dischargeports are aligned along the corresponding branch flow channels and thusincrease in the flow path area can be suppressed, for example, incomparison to a case where the plurality of discharge ports are alignedin a direction orthogonal to the branch flow channels. Enlargement ofthe nozzle can thereby be suppressed.

The main body is preferably formed of a quartz-containing material.Quartz is higher in strength than, for example, a resin. Thus, byforming the main body from a quartz-containing material, enlargement ofthe nozzle can be suppressed while securing strength of the nozzle.Further, quartz has resistance against chemicals. Thus, by forming themain body from a quartz-containing material, corrosion of the nozzle canbe suppressed or prevented.

The main body is not restricted to being formed of a quartz-containingmaterial and may be formed of any one of resin-containing materials,metal-containing materials, and ceramic-containing materials. However, aresin is lower in strength than quartz and an adequate strength may notbe secured in the nozzle. Also, in a case where the main body is formedof a metal-containing material, the metal may elute into the processingliquid flowing inside the nozzle, and the substrate may becomecontaminated by the metal dissolved in the processing liquid. Also, aceramic is porous and thus in a case where the main body is formed of aceramic-containing material, a portion of the main body may break offand a piece of the main body may be supplied to the substrate. It isthus preferable for the main body to be formed of a quartz-containingmaterial.

Also preferably, the nozzle further includes a wiring connected to thepiezo element and a cover covering both the piezo element and the wiringtherewithin. With this arrangement, the piezo element and the wiring(electrical wiring) are protected by the cover. Thus, even in a casewhere the nozzle is used in a chemical solution atmosphere, exposure ofthe piezo element and the wiring to the chemical solution atmosphere canbe suppressed or prevented. Corrosion of the piezo element and thewiring due to contact with the chemical solution can thus be suppressedor prevented.

Preferably, the main body further includes connection channelsconnecting the branch flow channels and the discharge ports. In thiscase, each connection channel preferably includes a reduced portion thatreduces in flow path area as the discharge port is approached.Preferably, the flow path area of the reduced portion reduces in acontinuous manner as the discharge port is approached.

With this arrangement, the processing liquid that flows through thebranch flow channels is discharged from the discharge ports via theconnection channels. The flow path area of the reduced portion providedin each connection channel reduces as the discharge port is approached.Lowering in pressure of the processing liquid in the connection channelcan thereby be reduced. Pressure loss in the connection channel can thusbe reduced. Also, in the case where the flow path area of the reducedportion reduces in a continuous manner, concentration of stress in theconnection channel can be suppressed or prevented.

Also preferably, the processing liquid flow passageway and theconnection channels are disposed in an interior of the main body and themain body includes a plurality of divided bodies that are joined to eachother. With this arrangement, the main body is formed by joining theplurality of divided bodies. The plurality of divided bodies can thus beformed individually. The processing liquid flow passageway and theconnection channels can thus be formed by joining the plurality ofdivided bodies having formed therein recess portions corresponding tothe processing liquid flow passageway and the connection channels. Thereduced portion provided in each connection channel is difficult to formfrom the discharge port side because the reduced portion reduces in flowpath area as the discharge port is approached. On the other hand, beforethe joining of the plurality of divided bodies, the reduced portions canbe formed from the branch flow channel side. The reduced portions canthus be formed readily.

The present invention also provides a substrate processing apparatusthat includes a substrate holding unit holding a substrate, a nozzlewith the above characteristics that discharges droplets of a processingliquid toward the substrate held by the substrate holding unit, aprocessing liquid supply unit supplying the processing liquid to thesupply port of the nozzle, and a voltage applying unit applying voltageto the piezo element of the nozzle.

With the substrate processing apparatus with the above arrangement, aplurality of droplets of the processing liquid can be sprayed from thenozzle by supplying the processing liquid from the processing liquidsupply unit to the nozzle and applying voltage to the piezo element bythe voltage applying unit. The droplets of the processing liquid canthereby be made to collide against the substrate held by the substrateholding unit and foreign substances attached to the substrate can beremoved physically by kinetic energy of the droplets. Further, forexample, by controlling pressure of the processing liquid supplied tothe nozzle and vibration of the piezo element, the variation in size andspeed of the droplets can be suppressed. Satisfactory cleaning can thusbe performed.

The substrate processing apparatus according to one embodiment of thepresent invention further includes a nozzle moving unit moving thenozzle along a locus, wherein the locus extends along a major surface ofthe substrate held by the substrate holding unit and passes through acenter of the major surface when viewed from a perpendicular directionperpendicular to the major surface, and holding the nozzle so that theplurality of columns formed by the plurality of discharge portsintersect the locus when viewed from the perpendicular direction. Themajor surface of the substrate may be a front surface of the substratethat is a device forming surface or may be a rear surface of thesubstrate that is a non-device forming surface.

With this arrangement, the nozzle moving unit moves the nozzle along thelocus that passes through the center of the major surface of thesubstrate when viewed from the direction perpendicular to the majorsurface. Further, the nozzle moving unit holds the nozzle so that whenviewed from the direction perpendicular to the major surface of thesubstrate, the plurality of columns formed by the plurality of dischargeports intersect the locus. That is, when viewed from the directionperpendicular to the major surface of the substrate, all the columnsintersect the locus. The droplets of the processing liquid sprayed fromall the columns can thus be made to collide successively against acentral portion of the major surface of the substrate by moving thenozzle along the locus while making the droplets of the processingliquid be sprayed from the nozzle. The central portion of the majorsurface of the substrate can thereby be cleaned satisfactorily.

The substrate processing apparatus may further include a control unitcontrolling the nozzle moving unit. In this case, the control unit maycontrol the nozzle moving unit to move the nozzle along the locus sothat, between a central position at which the nozzle overlaps with thecenter of the major surface when viewed from the perpendicular directionand a peripheral edge position at which the nozzle overlaps with aperipheral edge of the major surface when viewed from the perpendiculardirection, the plurality of columns overlap successively with the centerof the major surface when viewed from the perpendicular direction. Also,the control unit may control the nozzle moving unit to move the nozzlealong the locus between a first peripheral edge position at which thenozzle overlaps with a peripheral edge of the major surface when viewedfrom the perpendicular direction and a second peripheral edge position,which is a position differing from the first peripheral edge positionand at which the nozzle overlaps with a peripheral edge of the majorsurface when viewed from the perpendicular direction.

In both the case of moving the nozzle between the central position andthe peripheral edge position and the case of moving the nozzle betweenthe first peripheral edge position and the second peripheral edgeposition, the droplets of the processing liquid sprayed from all thecolumns can be made to collide successively against the central portionof the major surface of the substrate. The central portion of the majorsurface of the substrate can thereby be cleaned satisfactorily. Also, inthe case of moving the nozzle between the central position and theperipheral edge position, a movement range of the nozzle is narrow incomparison to the case of moving the nozzle between the first peripheraledge position and the second peripheral edge position. Thus, by movingthe nozzle between the central position and the peripheral edgeposition, space inside the substrate processing apparatus can be usedeffectively.

The present invention further provides a substrate processing methodthat includes a step of supplying a processing liquid to the supply portof the nozzle with the above-described characteristics in a state wherethe nozzle faces a major surface of a substrate and a step of applyingvoltage to the piezo element of the nozzle in parallel to the step ofsupplying the processing liquid. By this method, the same effects as theeffects described in relation to the present invention of the substrateprocessing apparatus can be exhibited.

Also, the present invention provides a substrate processing apparatusthat includes a substrate holding and rotating unit that holds androtates a substrate, a nozzle having disposed therein a plurality ofcolumns, in each of which a plurality of discharge ports dischargingdroplets of a processing liquid are aligned in a single column, anddischarging the droplets of the processing liquid toward the substrateheld by the substrate holding and rotating unit, and a nozzle holdingand moving unit moving the nozzle along a locus, wherein the locuspasses through a rotation center of a major surface of the substrateheld by the substrate holding and rotating unit when viewed from aperpendicular direction perpendicular to the major surface, and holdingthe nozzle so that the plurality of columns intersect the locus whenviewed from the perpendicular direction.

With this arrangement, the nozzle holding and moving unit moves thenozzle along the locus that passes through the center of the majorsurface of the substrate when viewed from the direction perpendicular tothe major surface. Further, the nozzle holding and moving unit holds thenozzle so that, when viewed from the direction perpendicular to themajor surface of the substrate, the plurality of columns formed by theplurality of discharge ports intersect the locus. That is, when viewedfrom the direction perpendicular to the major surface of the substrate,all the columns intersect the locus. The droplets of the processingliquid sprayed from all the columns can thus be made to collide againsta central portion of the major surface of the substrate successively bymoving the nozzle along the locus while making the droplets of theprocessing liquid be sprayed from the nozzle. The central portion of themajor surface of the substrate can thereby be cleaned satisfactorily.

Japanese Unexamined Patent Application Publication No. 2011-29315discloses a substrate processing apparatus that includes a cleaning headthat forms droplets of a processing liquid by applying vibration to theprocessing liquid. The cleaning head includes a tubular body providedwith a plurality of hole columns, in each of which a plurality ofdischarge holes are aligned in a single column, and a piezo elementmounted to the tubular body. The processing liquid is supplied to aninterior of the tubular body. When an AC voltage is applied to the piezoelement, vibration is applied to the processing liquid inside thetubular body and droplets of the processing liquid are sprayed from theplurality of discharge holes. When a substrate cleaning process isperformed with this substrate processing apparatus, the cleaning head isscanned between an upper side of a central portion and an upper side ofan edge portion of the substrate while rotating the substrate. If inthis process, the cleaning head is scanned in the same direction as adirection of alignment of the hole columns of the discharge holesprovided in the cleaning head, then at the central portion of thesubstrate, only the droplets of the processing liquid discharged from aportion of the hole columns among the plurality of hole columns providedin the cleaning head are supplied to the central portion of thesubstrate and there are thus cases where the central portion of thesubstrate is not cleaned adequately.

The substrate processing apparatus described above provides a unit thatresolves this issue and realizes a substrate processing apparatus thatcan adequately clean an entire surface of the substrate.

A control unit may further be included that controls the nozzle holdingand moving unit to move the nozzle along the locus so that, between acentral position at which the nozzle overlaps with the rotation centerof the major surface when viewed from the perpendicular direction and aperipheral edge position at which the nozzle overlaps with a peripheraledge of the major surface when viewed from the perpendicular direction,the plurality of columns overlap successively with the rotation centerof the major surface when viewed from the perpendicular direction.

With this arrangement, the droplets of the processing liquid sprayedfrom all the columns can be made to collide successively against thecentral portion of the major surface of the substrate. The centralportion of the major surface of the substrate can thereby be cleanedsatisfactorily. Also, in the case of moving the nozzle between thecentral position and the peripheral edge position, the movement range ofthe nozzle is narrow in comparison to the case of moving the nozzlebetween a first peripheral edge position and a second peripheral edgeposition that differs from the first peripheral edge position. Thus, bymoving the nozzle between the central position and the peripheral edgeposition, space inside the substrate processing apparatus can be usedeffectively.

The nozzle may further include a main body having processing liquid flowchannels, which are connected to the discharge ports and in which theprocessing liquid flows through along the columns, provided inrespective correspondence to each of the plurality of columns and apiezo element applying vibration to the processing liquid flowingthrough the processing liquid flow channels, and a voltage applying unitthat applies voltage to the piezo element may further be included.

With this arrangement, a plurality of droplets of the processing liquidcan be sprayed from the nozzle by applying voltage to the piezo elementby the voltage applying unit while making the processing liquid flowthrough the processing liquid flow channels. The droplets of theprocessing liquid can thereby be made to collide against the substrateheld by the substrate holding unit and foreign substances attached tothe substrate can be removed physically by the kinetic energy of thedroplets. Further, for example, by controlling the pressure of theprocessing liquid supplied to the nozzle and the vibration of the piezoelement, the variation in size and speed of the droplets can besuppressed. Satisfactory cleaning can thus be performed.

Further, the present invention provides a substrate processing methodthat includes a substrate holding and rotating step of holding androtating a substrate and a nozzle moving step of moving a nozzle, havingdisposed therein a plurality of columns, in each of which a plurality ofdischarge ports discharging droplets of a processing liquid are alignedin a single column, and discharging the droplets of the processingliquid toward the substrate, along a locus passing through a rotationcenter of a major surface of the substrate when viewed from aperpendicular direction perpendicular to the major surface. In thenozzle moving step, the nozzle is held so that, when viewed from theperpendicular direction, the plurality of columns intersect the locus.An entire surface of the substrate can be cleaned adequately by thismethod.

In the nozzle moving step, the nozzle may be moved along the locus sothat, between a central position at which the nozzle overlaps with therotation center of the major surface when viewed from the perpendiculardirection and a peripheral edge position at which the nozzle overlapswith a peripheral edge of the major surface when viewed from theperpendicular direction, the plurality of columns overlap successivelywith the rotation center of the major surface when viewed from theperpendicular direction.

The aforementioned and other objects, features, and effects of thepresent invention shall be clarified by the following description ofembodiments given below with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of a general arrangement of a substrateprocessing apparatus according to a first embodiment of the presentinvention.

FIG. 2 is a plan view of a spray nozzle and an arrangement relatedthereto according to the first embodiment of the present invention.

FIG. 3 is a schematic side view of the spray nozzle according to thefirst embodiment of the present invention.

FIG. 4 is a schematic exploded perspective view of the spray nozzleaccording to the first embodiment of the present invention.

FIG. 5 is a plan view for explaining an arrangement of a main bodyincluded in the spray nozzle according to the first embodiment of thepresent invention.

FIG. 6 is a sectional view of the main body taken along the line VI-VIin FIG. 5.

FIG. 7 is a sectional view of the main body taken along the line VII-VIIin FIG. 5.

FIG. 8 is a partially enlarged view of FIG. 6.

FIG. 9A to FIG. 9D are diagrams for describing a processing example of asubstrate performed by the substrate processing apparatus according tothe first embodiment of the present invention.

FIG. 10 is a plan view of a state where the spray nozzle is positionedat a central position.

FIG. 11 is a plan view of a spray nozzle and an arrangement relatedthereto according to a second embodiment of the present invention.

FIG. 12 is a plan view of a state immediately before the spray nozzlereaches a central position.

FIG. 13 is a plan view of a state in which the spray nozzle ispositioned at the central position.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 is a schematic view of a general arrangement of a substrateprocessing apparatus 1 according to a first embodiment of the presentinvention.

FIG. 2 is a plan view of a spray nozzle 4 and an arrangement relatedthereto according to the first embodiment of the present invention.

The substrate processing apparatus 1 is a substrate processing apparatusof the single-substrate treatment type that processes circularsubstrates W, such as semiconductor wafers, one by one. The substrateprocessing apparatus 1 includes a spin chuck 2 (substrate holding unit,substrate holding and rotating unit) that horizontally holds and rotatesa substrate W, a tubular cup 3 that surrounds the spin chuck 2, thespray nozzle 4 that supplies droplets of a processing liquid to thesubstrate W held by the spin chuck 2, a first rinsing liquid nozzle 5and a second rinsing liquid nozzle 6 that supply a rinsing liquid to thesubstrate W held by the spin chuck 2, and a control device 7 (controlunit) that controls operations of the spin chuck 2 and other devicesincluded in the substrate processing apparatus 1 and controls openingand closing of valves. The spray nozzle 4 is an example of a nozzleaccording to the present invention.

The spin chuck 2 includes a spin base 8 that horizontally holds thesubstrate W and is capable of rotating the substrate W around a verticalaxis passing through a center of the substrate W and a spin motor 9 thatrotates the spin base 8 around the vertical axis. The spin chuck 2 maybe a gripping type chuck that horizontally holds the substrate W bygripping the substrate W in a horizontal direction, or, alternatively,may be a vacuum-type chuck that horizontally holds the substrate W bysuction of a rear surface (lower surface) of the substrate W, which is anon-device forming surface. In the first embodiment, the spin chuck 2 isa gripping type chuck. The spin motor 9 is controlled by the controldevice 7.

The spray nozzle 4 is arranged to spray a plurality of droplets of theprocessing liquid downwards. The spray nozzle 4 is connected to aprocessing liquid supply mechanism 11 (processing liquid supply unit)via a processing liquid supply pipe 10. Further, the spray nozzle 4 isconnected to a processing liquid drain pipe 13 in which a drain valve 12is interposed. The processing liquid supply mechanism 11 is, forexample, a mechanism that includes a pump. The processing liquid supplymechanism 11 constantly supplies the processing liquid at apredetermined pressure (of, for example, no more than 10 MPa) to thespray nozzle 4. As examples of the processing liquid supplied from theprocessing liquid supply mechanism 11 to the spray nozzle 4, deionizedwater, carbonated water, a mixed liquid of ammonia water and hydrogenperoxide solution, etc., can be cited. By controlling the processingliquid supply mechanism 11, the control device 7 can change the pressureof the processing liquid supplied to the spray nozzle 4 to any pressure.

Also, as shown in FIG. 1, the spray nozzle 4 includes a piezo element 14disposed in an interior of the spray nozzle 4. The piezo element 14 isconnected to a voltage applying mechanism 16 (voltage applying unit) viaa wiring 15. The voltage applying mechanism 16 is, for example, amechanism that includes an inverter. The voltage applying mechanism 16applies an AC voltage to the piezo element 14. When the AC voltage isapplied to the piezo element 14, the piezo element 14 vibrates at afrequency corresponding to a frequency of the applied AC voltage. Bycontrolling the voltage applying mechanism 16, the control device 7 canchange the frequency of the AC voltage applied to the piezo element 14to any frequency (for example, from several hundred (kHz to severalMHz). The frequency of vibration of the piezo element 14 is thuscontrolled by the control device 7.

The substrate processing apparatus 1 further includes a nozzle movingmechanism 17 (nozzle holding and moving unit) that moves the spraynozzle 4. The nozzle moving mechanism 17 includes a nozzle arm 18holding the spray nozzle 4, a rotating mechanism 19 connected to thenozzle arm 18, and a raising and lowering mechanism 20 connected to therotating mechanism 19. The rotating mechanism 19 is, for example, amechanism that includes a motor. The raising and lowering mechanism 20is a mechanism that includes a ball screw mechanism and a motor thatdrives the ball screw mechanism. The rotating mechanism 19 rotates thenozzle arm 18 around a vertical rotational axis A1 disposed at aperiphery of the spin chuck 2. The spray nozzle 4 is rotated around therotational axis A1 together with the nozzle arm 18. The spray nozzle 4is thereby moved in a horizontal direction. The raising and loweringmechanism 20 raises and lowers the rotating mechanism 19 in a verticaldirection D1. The spray nozzle 4 and the nozzle arm 18 are raised andlowered in the vertical direction D1 together with the rotatingmechanism 19. The spray nozzle 4 is thereby moved in the verticaldirection D1.

The rotating mechanism 19 moves the spray nozzle 4 horizontally within ahorizontal plane that includes a region above the spin chuck 2 and aposition separated from the region above the spin chuck 2. Further, asshown in FIG. 2, the rotating mechanism 19 moves the spray nozzle 4horizontally along an arcuate locus X1 extending along an upper surfaceof the substrate W held by the spin chuck 2. The locus X1 is a curvethat joins two non-overlapping positions on the upper surface of thesubstrate W when viewed from a perpendicular direction perpendicular tothe upper surface of the substrate W held by the spin chuck 2 (thevertical direction D1 in the first embodiment) and passes through acenter C1 of the upper surface of the substrate W when viewed from thevertical direction D1. In a state where the spray nozzle 4 is positionedabove the substrate W held by the spin chuck 2, the raising and loweringmechanism 20 lowers the spray nozzle 4, so that the spray nozzle 4 ismoved close to the upper surface of the substrate W. When droplets ofthe processing liquid sprayed from the spray nozzle 4 are to be suppliedto the substrate W, the control device 7 controls the rotating mechanism19 to move the spray nozzle 4 horizontally along the locus X1 with thespray nozzle 4 being disposed close to the upper surface of thesubstrate W.

As shown in FIG. 1, the first rinsing liquid nozzle 5 is connected to afirst rinsing liquid supply pipe 22 in which a first rinsing liquidvalve 21 is interposed. Supplying of the rinsing liquid to the firstrinsing liquid nozzle 5 is controlled by opening and closing of thefirst rinsing liquid valve 21. The rinsing liquid supplied to the firstrinsing liquid nozzle 5 is discharged toward an upper surface centralportion of the substrate W held by the spin chuck 2. The second rinsingliquid 6 is connected to a second rinsing liquid supply pipe 24 in whicha second rinsing liquid valve 23 is interposed. Supplying of the rinsingliquid to the second rinsing liquid nozzle 6 is controlled by openingand closing of the second rinsing liquid valve 23. The rinsing liquidsupplied to the second rinsing liquid nozzle 6 is discharged downwardfrom the second rinsing liquid nozzle 6. As examples of the rinsingliquid supplied to the first rinsing liquid nozzle 5 and the secondrinsing liquid nozzle 6, deionized water, carbonated water, electrolyzedion water, hydrogen water, ozone water, and aqueous hydrochloric acid ofdilute concentration (for example of about 10 to 100 ppm) can be cited.

The second rinsing liquid nozzle 6 is fixed to the spray nozzle 4 by astay 25. The second rinsing liquid nozzle 6 is moved together with thespray nozzle 4 in the horizontal direction and the vertical directionD1. The second rinsing liquid nozzle 6 is thus moved horizontally alongthe locus X1 together with the spray nozzle 4. As shown in FIG. 2, thespray nozzle 4 and the second rinsing liquid nozzle 6 are aligned in arotation direction D2 of the substrate W by the spin chuck 2. Therinsing liquid supplied to the second rinsing liquid nozzle 6 may bedischarged toward a region below the spray nozzle 4 or may be suppliedto a position, which, in regard to the rotation direction D2 of thesubstrate W, is located upstream and close to a supply position to whichthe droplets of the processing liquid are supplied from the spray nozzle4 to the upper surface of the substrate W.

FIG. 3 is a schematic side view of the spray nozzle 4 according to thefirst embodiment of the present invention. FIG. 4 is a schematicexploded perspective view of the spray nozzle 4 according to the firstembodiment of the present invention.

The spray nozzle 4 includes a main body 26 that discharges the dropletsof the processing liquid, a cover 27 mounted to the main body 26, thepiezo element 14 covered by the cover 27, and a seal 28 interposedbetween the main body 26 and the cover 27. The main body 26 and thecover 27 are both formed of a material with chemical resistance. In thefirst embodiment, the main body 26 is formed, for example, of quartz.The cover 27 is formed, for example, of a fluorine-based resin. The seal28 is formed, for example, of a resin material with elasticity, such asEPDM (ethylene-propylene-diene rubber). The main body 26 has a strengthcapable of withstanding a high pressure. The piezo element 14 and aportion of the main body 26 are housed in an interior of the cover 27.An end portion of the wiring 15 is connected, for example by solder,within the cover 27, to the piezo element 14. The interior of the cover27 is sealed by the seal 28.

FIG. 5 is a plan view for explaining an arrangement of the main body 26included in the spray nozzle 4 according to the first embodiment of thepresent invention. FIG. 6 is a sectional view of the main body 26 takenalong the line VI-VI in FIG. 5. FIG. 7 is a sectional view of the mainbody 26 taken along the line VII-VII in FIG. 5. FIG. 8 is a partiallyenlarged view of FIG. 6. FIG. 5 and FIG. 6 shall be referenced in thefollowing description. Also, FIG. 1, FIG. 2, FIG. 4, FIG. 7, and FIG. 8shall be referenced where suitable in the following description.

The main body 26 includes a supply port 29 supplied with the processingliquid, a drain port 30 from which the processing liquid supplied to thesupply port 29 is drained, a processing liquid flow passageway 31connecting the supply port 29 and the drain port 30, a plurality ofconnection channels 32 connected to the processing liquid flowpassageway 31, and a plurality of discharge ports 33 connectedrespectively to the plurality of connection channels 32. The processingliquid flow passageway 31 and the connection channels 32 are disposed inan interior of the main body 26. The supply port 29, the drain port 30,and the discharge ports 33 open at surfaces of the main body 26. Thesupply port 29 and the drain port 30 are positioned higher than thedischarge ports 33. A lower surface of the main body 26 is, for example,a flat surface, and the discharge ports 33 open at the lower surface ofthe main body 26. The processing liquid supply pipe 10 and theprocessing liquid drain pipe 13 are connected to the supply port 29 andthe drain port 30, respectively. The processing liquid flowing throughthe processing liquid supply pipe 10 is supplied to the supply port 29.The processing liquid discharged from the drain port 30 is drained intothe processing liquid drain pipe 13.

The processing liquid flow passageway 31 includes an upstream sidecollecting flow channel 34 connected to the supply port 29, a downstreamside collecting flow channel 35 connected to the discharge port 30, andtwo branch flow channels 36 (processing liquid flow channels) connectedto the upstream side collecting flow channel 34 and the downstream sidecollecting flow channel 35. The upstream side collecting flow channel 34and the downstream side collecting flow channel 35 extend verticallydownward from the supply port 29 and the drain port 30, respectively.One end of each branch flow channel 36 is connected to a lower end ofthe upstream side collecting flow channel 34 and the other end of eachbranch flow channel 36 is connected to a lower end of the downstreamside collecting flow channel 35. The lower end of the upstream sidecollecting flow channel 34 is a branching position and a lower end ofthe downstream side collecting flow channel 35 is a collecting position.The two branch flow channels 36 extend horizontally from the branchingposition to the collecting position. As shown in FIG. 5, the two branchflow channels 36 take on a rectangular shape in a plan view having fourarcuate corner portions that are outwardly convex. The two branch flowchannels 36 are orthogonal to the upstream side collecting flow channel34 and the downstream side collecting flow channel 35. With theexception of middle portions 39 to be described later, a cross-sectionalshape of the processing liquid flow passageway 31 is, for example, acircular shape with a diameter of no more than several mm.

Each branch flow channel 36 includes an upstream portion 37 connected tothe lower end of the upstream side collecting flow channel 34, adownstream portion 38 connected to the lower end of the downstream sidecollecting flow channel 35, and the middle portion 39 connected to theupstream portion 37 and the downstream portion 38. As shown in FIG. 5,the two upstream portions 37 extend to mutually opposite sides from thelower end of the upstream side collecting flow channel 34. Likewise, thetwo downstream portions 37 extend to mutually opposite sides from thelower end of the downstream side collecting flow channel 35. Each middleportion 39 extends rectilinearly from the upstream portion 37 to thedownstream portion 38. The two middle portions 39 are parallel. Eachmiddle portion 39 is not restricted to being rectilinear and may extendcurvingly. At least a portion of each middle portion 39 is positionedbelow the piezo element 14. Vibration from the piezo element 14 isapplied to the processing liquid flowing through each middle portion 39.In addition, a flow path area of the middle portion 39 is larger thanthe flow path areas of the upstream positions 37 and the downstreampositions 38. The middle portions 39 are connected to the upstreamportions 37 and the downstream portions 38 in a manner such that theflow path area changes in a continuous manner. As shown in FIG. 7, eachmiddle portion 39 has a cross-sectional shape of elliptical form that islong in the horizontal direction (cross-sectional shape orthogonal tothe middle portion 39). Each middle portion 39 is connected to aplurality of connection channels 32.

As shown in FIG. 6, each connection channel 32 extends verticallydownward from a lower portion of the middle portion 39. The connectionchannels 32 are orthogonal to the middle portion 39. Each discharge port32 is connected to one of either branch flow channel 36 via a connectionchannel 32. The cross-sectional shape of each connection channel 32 is,for example, a circular shape with a diameter of no more than severalmm. Each discharge port 33 is a microscopic hole having a diameter ofseveral μm to several dozen μm. The flow path area of each connectionchannel 32 is smaller than the flow path area of the branch flow channel36. The flow path area of each discharge port 33 is smaller than theflow path area of the connection channel 32. As shown in FIG. 7, eachconnection channel 32 includes a conical reduced portion 40 that reducescontinuously in flow path area as the discharge port 33 is approached.The discharge port 33 is connected to a lower end of the reduced portion40 that corresponds to a lower end of the connection channel 32. Aconnection channel 32 and a discharge port 33 that correspond to eachother are coaxial. As shown in FIG. 5, the plurality of discharge ports33 connected to the same branch flow channel 36 form two columns L1.Thus, in the first embodiment, the plurality of discharge ports 33 formfour columns L1.

Each column L1 is formed from several (for example, no less than ten)discharge ports 33. Each column L1 extends rectilinearly along thecorresponding branch flow channel 36. Each column L1 is not restrictedto being rectilinear and may extend curvingly. The four columns L1 areparallel. Two columns L1 corresponding to the same branch flow channel36 are adjacent to each other. An interval between such two columns L1is, for example, no more than several mm. The plurality of dischargeports 33 making up the same column L1 are aligned at equal intervals. Aninterval between two adjacent discharge ports 33 in the same column L1is, for example, no more than several mm and is constant in all thecolumns L1. As shown in FIG. 8, in two columns L1 corresponding to thesame branch flow channel 36, the plurality of discharge ports 33 makingup one column L1 (discharge ports 33 a in FIG. 8) and the plurality ofdischarge ports 33 making up the other column L1 (discharge ports 33 bin FIG. 8) are disposed in an alternating manner when viewed from ahorizontal direction orthogonal to the two columns L1. Thus, as shown inFIG. 5, the two columns L1 corresponding to the same branch flow channel36 are shifted in a longitudinal direction of the branch flow channel36.

As shown in FIG. 2, the nozzle moving mechanism 17 moves the spraynozzle 4 horizontally along the arcuate locus X1. The nozzle arm 18holds the spray nozzle 4 so that, when viewed from the verticaldirection D1, one of the middle portions 39 lies along a tangent to thelocus X1. The two columns L1 corresponding to the one middle portion 39thus extend along the tangent to the locus X1. The other middle portion39 is disposed at an inner side or an outer side of the locus X1. Whenthe nozzle moving mechanism 17 moves the spray nozzle 4 horizontallyalong the locus X1, the two columns L1 corresponding to the one middleportion 39 move along the locus X1.

Also, as shown in FIG. 4, the main body 26 includes an upper dividedbody 41 (divided body) and a lower divided body 42 (divided body). Boththe upper divided body 41 and the lower divided body 42 are formed ofquartz. The upper divided body 41 is disposed above the lower dividedbody 42. The upper divided body 41 and the lower divided body 42 arejoined to each other, for example, by welding. The plurality of branchflow channels 36 are formed between the upper divided body 41 and thelower divided body 42. That is, as shown in FIG. 6, a lower recessportion 43 that is recessed downward from an upper surface of the lowerdivided body 42 is formed in an upper surface of the lower divided body42, and an upper recess portion 44 that is recessed upward from a lowersurface of the upper divided body 42 is formed in a lower surface of theupper divided body 41. The upper divided body 41 and the lower dividedbody 42 are joined to each other in a state where the upper recessportion 44 and the lower recess portion 43 overlap vertically. Theprocessing liquid flow passageway 31 and the connection channels 32 areformed by the upper recess portion 44 and the lower recess portion 43.

The processing liquid supply mechanism 11 (see FIG. 1) constantlysupplies the processing liquid at a high pressure to the spray nozzle 4.The processing liquid supplied to the supply port 29 from the processingliquid supply mechanism 11 via the processing liquid supply pipe 10 issupplied to the processing liquid flow passageway 31. In a state wherethe drain valve 12 (see FIG. 1) is closed, the pressure (liquidpressure) of the processing liquid in the processing liquid flowpassageway 31 increases adequately. Thus, in the state where the drainvalve 12 is closed, the processing liquid is sprayed from the respectivedischarge ports 33 by the liquid pressure. Further, when in the statewhere the drain valve 12 is closed, the AC voltage is applied to thepiezo element 14, the vibration of the piezo element 14 is applied tothe processing liquid flowing through the branch flow channels 16, andthe processing liquid sprayed from the respective discharge ports 33 isdisrupted by the vibration. Thus, when the AC voltage is applied to thepiezo element 14 in the state where the drain valve 12 is closed,droplets of the processing liquid are sprayed from the respectivedischarge ports 33. Numerous droplets of the processing liquid ofuniform particle diameter are thereby sprayed simultaneously at uniformspeed.

On the other hand, when the drain valve 12 is open, the processingliquid supplied to the processing liquid flow passageway 31 is drainedfrom the drain port 30 to the processing liquid drain pipe 13. Also,pressure loss at portions of connection of the connection channels 32and the discharge ports 33 is large because the discharge ports 33 areextremely small in diameter. In the state where the drain valve 12 isopen, the liquid pressure in the processing liquid flow passageway 31does not rise adequately. Thus, in the state where the drain valve 12 isopen, the processing liquid supplied to the processing liquid flowpassageway 31 is drained to the processing liquid drain pipe 13 from thedrain port 30 and the processing liquid is not discharged from theplurality of discharge ports 33. The discharge of the processing liquidfrom the discharge ports 33 is thus controlled by the opening andclosing of the drain valve 12. The control device 7 opens the drainvalve 12 while the spray nozzle 4 is not used for processing thesubstrate W (during standby of the spray nozzle 4). A state where theprocessing liquid flows through the interior of the spray nozzle 4 isthus maintained even during standby of the spray nozzle 4.

FIG. 9A to FIG. 9D are diagrams for describing a processing example of asubstrate W performed by the substrate processing apparatus 1 accordingto the first embodiment of the present invention. FIG. 10 is a plan viewof a state where the spray nozzle 4 is positioned at a central positionPc1. FIG. 1 and FIG. 9A to FIG. 9D shall be referenced in the followingdescription. Also, FIG. 2 and FIG. 10 shall be referenced where suitablein the following description.

An unprocessed substrate W is conveyed by an unillustrated conveyingrobot and placed on the spin chuck 2 with a front surface, which is adevice forming surface, being faced upward. The control device 7 thencontrols the spin chuck 2 and makes spin chuck 2 hold the substrate W.Thereafter, the control device 7 controls the spin motor 9 to rotate thesubstrate W held by the spin chuck 2. When the substrate W is beingconveyed onto the spin chuck 2, the control device 7 controls the spraynozzle 4, etc., to be withdrawn from above the spin chuck 2.

A first cover rinse process of supplying deionized water, which is oneexample of the rinsing liquid, from the first rinsing liquid nozzle 5 tothe substrate W and covering the upper surface of the substrate W withdeionized water is then performed. Specifically, while making the spinchuck 2 rotate the substrate W, the control device 7 opens the firstrinsing liquid valve 21 to make deionized water be discharged from thefirst rinsing liquid nozzle 5 onto the upper surface central portion ofthe substrate W held by the spin chuck 2 as shown in FIG. 9A. Thedeionized water discharged from the first rinsing liquid nozzle 5 issupplied to the upper surface central portion of the substrate W andspreads to outer sides along the upper surface of the substrate W uponreceiving a centrifugal force due to the rotation of the substrate W.Deionized water is thereby supplied to the entire upper surface of thesubstrate W and the entire upper surface of the substrate W is coveredby deionized water. After elapse of a predetermined time from theopening of the first rinsing liquid valve 21, the control device 7closes the first rinsing liquid valve 21 and stops the discharging ofdeionized water from the first rinsing liquid nozzle 5.

Next, a cleaning process of supplying droplets of deionized water, whichis an example of the processing liquid, from the spray nozzle 4 to thesubstrate W and cleaning the substrate W and a second cover rinseprocess of supplying deionized water, which is one example of therinsing liquid, from the second rinsing liquid nozzle 6 to the substrateW and covering the upper surface of the substrate W with deionized waterare performed in parallel. Specifically, the control device 7 controlsthe nozzle moving mechanism 17 to move the spray nozzle 4 to above thespin chuck 2 and bring the spray nozzle 4 close to the upper surface ofthe substrate W. Thereafter, while making the spin chuck 2 rotate thesubstrate W, the control device 7 opens the second rinsing liquid valve23 to make deionized water be discharged from the second rinsing liquidnozzle 6 toward the region below the spray nozzle 4 as shown in FIG. 9B.In this state, the control device 7 closes the drain valve 12 andcontrols the voltage applying mechanism 16 and applies the AC voltage ofthe predetermined frequency to the piezo element 14 of the spray nozzle4.

The control device 7 controls the nozzle moving mechanism 17 to move thespray nozzle 4 horizontally along the locus X1 with the drain valve 12being closed and the AC voltage of the predetermined frequency beingapplied to the piezo element 14. Specifically, as shown in FIG. 2 andFIG. 9B, the control device 7 makes the spray nozzle 4 reciprocatebetween the central position Pc1 and a peripheral edge position Pe1 aplurality of times. The central position Pc1 is a position at which thespray nozzle 4 overlaps with a center C1 of the upper surface of thesubstrate W when viewed from the vertical direction D1 and theperipheral edge position Pe1 is a position at which the spray nozzle 4and a peripheral edge of the substrate W overlap when viewed from thevertical direction D1. In the state where the spray nozzle 4 ispositioned at the central position Pc1 as shown in FIG. 10, the onemiddle portion 39 and the center C1 of the upper surface of thesubstrate W overlap when viewed from the vertical direction D1. Further,in the state where the spray nozzle 4 is positioned between the centralposition Pc1 and the peripheral edge position Pe1 as shown in FIG. 2,the second rinsing liquid nozzle 6 is positioned at an upstream side ofthe spray nozzle 4 in relation to the rotation direction D2 of thesubstrate W. The control device 7 thus move the spray nozzle 4 in arange in which the second rinsing liquid nozzle 6 is positioned at theupstream side of the spray nozzle 4 in relation to the rotationdirection D2 of the substrate W.

As mentioned above, when the AC voltage is applied to the piezo element14 in the state where the drain valve 12 is closed, numerous droplets ofdeionized water are sprayed downward from the spray nozzle 4. Thenumerous droplets of deionized water are thereby supplied to the uppersurface of the substrate W that is covered by deionized water. Thus, bythe nozzle moving mechanism 17 moving the spray nozzle 4 between thecentral position Pc1 and the peripheral edge position Pe1, the numerousdroplets sprayed from the spray nozzle 4 are supplied across the entireupper surface of the substrate W. Also, the deionized water supplied bythe second rinsing liquid nozzle 6 is discharged toward the region belowthe spray nozzle 4. The droplets of deionized water sprayed from thespray nozzle 4 are thus sprayed onto a portion of the upper surface ofthe substrate W that is covered by the deionized water discharged fromthe second rinsing liquid nozzle 6. The numerous droplets sprayed fromthe spray nozzle 4 thus collide against the upper surface of thesubstrate W that is covered by deionized water.

Particles and other foreign substances attached to the upper surface ofthe substrate W are physically removed by kinetic energy of the dropletssprayed onto the upper surface of the substrate W. The upper surface ofthe substrate W is thereby cleaned. Further, droplets of deionized waterare sprayed onto the upper surface of the substrate W that is covered bydeionized water and thus damaging of the upper surface of the substrateW is suppressed or prevented. Yet further, droplets of deionized waterare sprayed onto the upper surface of the substrate W that is covered bydeionized water and thus foreign substances removed from the uppersurface of the substrate W by collision of the droplets can besuppressed or prevented from reattaching to the upper surface of thesubstrate W. When the cleaning process and the second cover rinseprocess have been performed for a predetermined time, the control device7 opens the drain valve 12 and at the same time closes the secondrinsing liquid valve 23 to stop the discharge of deionized water fromthe spray nozzle 4 and the second rinsing liquid nozzle 6.

Next, a rinse process of supplying deionized water, which is an exampleof the rinsing liquid, from the first rinsing liquid nozzle 5 to thesubstrate W is performed to rinse off the deionized water attached tothe substrate W or a chemical solution attached to the substrate W in acase where a chemical solution is discharged as the rinsing liquid fromthe second rinsing liquid nozzle 6. Specifically, while making the spinchuck 2 rotate the substrate W, the control device 7 opens the firstrinsing liquid valve 21 to make deionized water be discharged from thefirst rinsing liquid nozzle 5 onto the upper surface central portion ofthe substrate W held by the spin chuck 2 as shown in FIG. 9C. Thedeionized water discharged from the first rinsing liquid nozzle 5 issupplied to the upper surface central portion of the substrate W andspreads to outer sides along the upper surface of the substrate W uponreceiving a centrifugal force due to the rotation of the substrate W.Deionized water is thereby supplied to the entire upper surface of thesubstrate W and the deionized water or chemical solution supplied to thesubstrate W from the spray nozzle 4 and the second rinsing liquid nozzle6 is thereby rinsed off. After elapse of a predetermined time from theopening of the first rinsing liquid valve 21, the control device 7closes the first rinsing liquid valve 21 and stops the discharging ofdeionized water from the first rinsing liquid nozzle 5.

Next, a drying process (spin drying) of drying the substrate W isperformed. Specifically, the control device 7 controls the spin motor 9to rotate the substrate W at a high rotation speed (for example, severalthousand rpm). A large centrifugal force is thereby made to act on thedeionized water attached to the substrate W and the deionized waterattached to the substrate W is spun off to a periphery of the substrateW as shown in FIG. 9D. The deionized water is thereby removed from thesubstrate W and the substrate W dries. After the drying process has beenperformed for a predetermined time, the control device 7 controls thespin motor 9 to stop the rotation of the substrate W by the spin chuck2. Thereafter, the processed substrate W is conveyed out from the spinchuck 2 by the conveying robot.

As described above, with the first embodiment, the plurality of dropletsof the processing liquid can be sprayed from the spray nozzle 4 bysupplying the processing liquid from the processing liquid supplymechanism 11 to the spray nozzle 4 and applying voltage to the piezoelement 14 by the voltage applying mechanism 16. The droplets of theprocessing liquid can thereby be made to collide against the substrate Wheld by the spin chuck 2 and the foreign substances attached to thesubstrate W can be removed physically by the kinetic energy of thedroplets. Further, by controlling the pressure of the processing liquidsupplied to the spray nozzle 4 and the vibration of the piezo element14, the variation in size and speed of the droplets can be suppressed.Satisfactory cleaning can thus be performed.

Also, with the first embodiment, the processing liquid flow passageway31 provided in the main body 26 of the spray nozzle 4 includes theplurality of branch flow channels 36. By branching the processing liquidflow passageway 31, the processing liquid flow passageway 31 can beincreased in total length. A larger number of discharge ports 33 canthereby be connected individually to the processing liquid flowpassageway 31. A larger number of droplets can thereby be sprayed at thesame time from the spray nozzle 4. Further, increase in a maximum flowpath area can be suppressed or prevented and thus enlargement of thespray nozzle 4 can be suppressed. Yet further, the plurality ofdischarge ports 33 are aligned along the corresponding branch flowchannel 36 and thus increase in the maximum flow path area can besuppressed. Enlargement of the spray nozzle 4 can thereby be suppressed.

Also, with the first embodiment, the main body 26 of the spray nozzle 4is formed of quartz. Quartz is higher in strength than, for example, aresin. Thus, by forming the main body 26 from quartz, enlargement of thespray nozzle 4 can be suppressed while securing strength of the spraynozzle 4. Further, quartz has resistance against chemicals. Thus, byforming the main body 26 from quartz, corrosion of the spray nozzle 4can be suppressed or prevented.

Also, with the first embodiment, the wiring 15 for applying voltage tothe piezo element 14 is connected to the piezo element 14 inside thecover 27. The piezo element 14 and the wiring 15 are thus protected bythe cover 27. Thus, even in a case where the spray nozzle 4 is used in achemical solution atmosphere, exposure of the piezo element 14 and thewiring 15 to the chemical solution atmosphere can be suppressed orprevented. Corrosion of the piezo element 14 and the wiring 15 due tocontact with the chemical solution can thus be suppressed or prevented.

Also, with the first embodiment, the connection channels 32 connectingthe branch flow channels 36 and the discharge ports 33 are disposed inthe main body 26 of the spray nozzle 4. The processing liquid that flowsthrough the branch flow channels 36 is discharged from the dischargeports 33 via the connection channels 32. Each of the connection channel32 includes the reduced portion 40 that reduces in flow path area as thedischarge port 33 is approached. The flow path area of the reducedportion 40 reduces in a continuous manner as the discharge port 33 isapproached. Lowering in pressure of the processing liquid in theconnection channel 32 can thereby be reduced. That is, pressure loss inthe connection channel 32 can be reduced. Also, concentration of stressin the connection channel 32 can be suppressed or prevented because theflow path area of the reduced portion 40 reduces in a continuous manner.

Also, with the first embodiment, the main body 26 is formed by joiningtogether the upper divided body 41 and the lower divided body 42. Theupper divided body 41 and the lower divided body 42 are formedindividually before being joined to each other. That is, the upperrecess portion 44 and the lower recess portion 43 that form theprocessing liquid flow passageway 31 and the connection channels 32 areformed in the upper divided body 41 and the lower divided body 42,respectively, before the upper divided body 41 and the lower dividedbody 42 are joined to each other. The reduced portions 40, which areprovided in the connection channels 32, are difficult to form from thedischarge port 33 side because each reduced portion 40 reduces in flowpath area as the discharge port 33 is approached. On the other hand,before the joining of the upper divided body 41 and the lower dividedbody 42, the reduced portions 40 can be formed from the branch flowchannel 36 side. The reduced portions 40 can thus be formed readily.

Also, with the first embodiment, the processing liquid drain pipe 13 isconnected to the drain port 30 of the spray nozzle 4 and the drain valve12 is interposed in the processing liquid drain pipe 13. In the statewhere the drain valve 12 is closed, the processing liquid supplied tothe supply port 29 of the spray nozzle 4 passes through the processingliquid flow passageway 31 and is discharged from the plurality ofdischarge ports 33. Also, in the state where the drain valve 12 is open,the processing liquid supplied to the supply port 29 of the spray nozzle4 passes through the processing liquid flow passageway 31 and is drainedfrom the drain port 30. Thus, in both the state where the drain valve 12is closed and the state where the drain valve 12 is open, retention ofthe processing liquid in the processing liquid flow passageway 31 isprevented. Occurrence of bacteria inside the spray nozzle 4 due toretention of the processing liquid can thereby be suppressed orprevented. Contamination of the substrate W due to supplying of dropletsof a processing liquid that contains bacteria to the substrate W canthus be suppressed or prevented.

Also, with the first embodiment, in the two columns L1 corresponding tothe same branch flow channel 36, the plurality of discharge ports 33making up one column L1 and the plurality of discharge ports 33 makingup the other column L1 are disposed in an alternating manner when viewedfrom the horizontal direction orthogonal to the two columns L1. That is,with the two different columns L1, the one column L1 includes thedischarge ports 33 that are disposed so as not to overlap with thedischarge ports 33 making up the other column L1 when viewed from anydirection orthogonal to the two columns L1. Thus, when the spray nozzle4 is moved while the plurality of droplets of the processing liquid aresupplied from the spray nozzle 4 to the upper surface of the substrateW, the range in which the droplets of the processing liquid collide withthe upper surface of the substrate W spreads and the droplets of theprocessing liquid are supplied uniformly to the upper surface of thesubstrate W. The time required for cleaning the substrate W can thus bereduced and uniformity of cleaning can be improved.

A second embodiment of the present invention shall now be described. Aprincipal point of difference of the second embodiment is the relativeposition of the spray nozzle 4 with respect to the locus X1. That is,whereas in the first embodiment, only a portion of the columns L1intersects the locus X1, in the second embodiment, all the columns L1intersect the locus X1. With FIG. 11 to FIG. 13 referred to below,component portions equivalent to portions indicated in FIG. 1 to FIG. 10described above are provided with the same reference symbols as in FIG.1, etc., and description thereof shall be omitted.

FIG. 11 is a plan view of the spray nozzle 4 and an arrangement relatedthereto according to the second embodiment of the present invention.FIG. 12 is a plan view of a state immediately before the spray nozzle 4reaches a central position Pc201. FIG. 13 is a plan view of a state inwhich the spray nozzle 4 is positioned at the central position Pc201.

With the exception of the nozzle arm and the stay, a substrateprocessing apparatus 201 according to the second embodiment has the samearrangement as the substrate processing apparatus 1 according to thefirst embodiment. That is, as shown in FIG. 11, a nozzle movingmechanism 217 (nozzle moving unit) included in the substrate processingapparatus 201 includes the nozzle arm 218. The nozzle arm 218 holds thespray nozzle 4 so that, when viewed from a perpendicular directionperpendicular to the upper surface of the substrate W held by the spinchuck 2 (the vertical direction D1 in the second embodiment), the fourcolumns L1 intersect the locus X1. The second rinsing liquid nozzle 6 isfixed to the spray nozzle 4 by a stay 225. The spray nozzle 4 and thesecond rinsing liquid nozzle 6 are aligned in the rotation direction D2of the substrate W by the spin chuck 2.

In cleaning the substrate W by discharging the droplets of theprocessing liquid from the spray nozzle 4, the control device 7 makesthe spray nozzle 4 reciprocate a plurality of times between the centralposition Pc201 at which the spray nozzle 4 overlaps with the center C1of the upper surface of the substrate W when viewed from the verticaldirection D1 and a peripheral edge position Pe201 at which the spraynozzle 4 and the peripheral edge of the substrate W overlap when viewedfrom the vertical direction D1 while rotating the substrate W by meansof the spin chuck 2. As shown in FIG. 13, the central position Pc201 isa position at which the middle portion 39 positioned at the peripheraledge position Pe201 side overlaps with the center C1 of the uppersurface of the substrate W when viewed from the vertical direction D1.In the state where the spray nozzle 4 is positioned at the centralposition Pc201, the two columns L1 corresponding to the middle portion39 positioned at the peripheral edge position Pe201 side are orthogonalto the tangential line of the locus X1 at the center C1. As shown inFIG. 11, in a state where the spray nozzle 4 is positioned between thecentral position Pc201 and the peripheral edge position Pe201, thesecond rinsing liquid nozzle 6 is positioned at the upstream side of thespray nozzle 4 in regard to the rotation direction D2 of the substrateW. The control device 7 thus moves the spray nozzle 4 in a range inwhich the second rinsing liquid nozzle 6 is positioned at the upstreamside of the spray nozzle 4 in regard to the rotation direction D2 of thesubstrate W.

Also, as shown in FIG. 12, immediately before the spray nozzle 4 reachesthe central position Pc201, the middle portion 39 that is positioned atthe opposite side with respect to the peripheral edge position Pe201overlaps with the center C1 of the upper surface of the substrate W whenviewed from the vertical direction D1. Also, as shown in FIG. 13, in thestate where the ejection nozzle 4 is positioned at the central positionPc201, the middle portion 39 positioned at the peripheral edge positionPe201 side overlaps with the center C1 of the upper surface of thesubstrate W when viewed from the vertical direction D1. The controldevice 7 thus moves the ejection nozzle 4 along the locus X1 so that,between the central position Pc201 and the peripheral edge positionPe201, all of the columns L1 overlap successively with the center C1 ofthe upper surface of the substrate W when viewed from the verticaldirection D1.

As described above, with the second embodiment, the nozzle movingmechanism 217 holds the spray nozzle 4 so that when viewed from thevertical direction D1, the plurality of columns L1 formed by theplurality of discharge ports 33 intersect the locus X1. That is, whenviewed from the vertical direction D1, all of the columns L1 intersectthe locus X1. The droplets of the processing liquid sprayed from all ofthe columns L1 can thus be made to collide successively against theupper surface central portion of the substrate W by moving the spraynozzle 4 along the locus X1 while making the droplets of the processingliquid be sprayed from the spray nozzle 4. On the other hand, in thecase where all of the columns L1 do not intersect the locus X1 as in thefirst embodiment, only the droplets of the processing liquid sprayedfrom a portion of the columns L1 (in the first embodiment, the twocolumns L1 corresponding to the one middle portion 39) are supplied tothe upper surface central portion of the substrate W. Thus, by makingall of the columns L1 intersect the locus X1, a number of times ofcollision of the droplets against the upper surface central portion ofthe substrate W can be increased. The upper surface central portion ofthe substrate W can thereby be cleaned satisfactorily.

Also, with the second embodiment, the control device 7 moves the spraynozzle 4 between the central position Pc201 and the peripheral edgeposition Pe201. A movement range of the spray nozzle 4 is thus narrow incomparison to a case of moving the spray nozzle 4 between two positions(a first peripheral edge position and a second peripheral edge position)at which the spray nozzle 4 overlaps with the upper surface peripheraledge of the substrate W when viewed from the vertical direction D1.Further, the second rinsing liquid nozzle 6 can be constantly positionedat the upstream side of the spray nozzle 4 in regard to the rotationdirection D2 of the substrate W because the control device 7 moves thespray nozzle 4 between the central position Pc201 and the peripheraledge position Pe201. The rinsing liquid discharged from the secondrinsing liquid nozzle 6 can thus be supplied in advance to the portionof the upper surface of the substrate W onto which the droplets of theprocessing liquid are sprayed. The portion of the upper surface of thesubstrate W onto which the droplets of the processing liquid are sprayedcan thereby be protected reliably by the rinsing liquid.

Although the embodiments of the present invention have been describedabove, the present invention is not limited to the contents of theabove-described first and second embodiments and can be variouslymodified within the scope of the appended claims.

For example, although with each of the first and second embodiments, acase where the processing liquid flow passageway 31 includes two branchflow channels 36 has been described, the processing liquid flowpassageway 31 may include three or more branch flow channels 36 instead.

Also, although with each of the first and second embodiments, a casewhere two columns L1 are provided in a single branch flow channel 36 hasbeen described, the number of columns L1 provided in a single branchflow channel 36 may be one or may be no less than three.

Also, although with each of the first and second embodiments, a casewhere two columns L1 are provided in each of the two branch flowchannels 36 has been described, the numbers of columns L1 provided inthe respective branch flow channels 36 may differ.

Also, although with each of the first and second embodiments, a casewhere the plurality of branch flow channels 36 branch at the lower endof the upstream side collecting flow channel 34 that is the branchingposition and collect together at the lower end of the downstream sidecollecting flow channel 35 that is the collecting position has beendescribed, a branching/collecting position may also be provided betweenthe branching position and the collecting position. That is, theplurality of branch flow channels 36 that branch at the branch positionmay collect together and re-branch at the branching/collecting positionand then collect together again at the collecting position.

Also, although with each of the first and second embodiments, a casewhere the interval between two adjacent discharge ports in the samecolumn L1 is fixed in all the columns L1 has been described, a column L1may be provided that includes two discharge ports 33 that are aligned atan interval that differs from that of the other columns L1.

Also, although with each of the first and second embodiments, a casewhere the plurality of discharge ports 33 making up the same column L1are aligned at equal intervals has been described, the plurality ofdischarge ports 33 making up the same column L1 do not have to bealigned at equal intervals.

Also, although with each of the first and second embodiments, a casewhere a single piezo element 14 is mounted to the upper surface of themain body 26 has been described, a plurality of piezo elements 14 may bemounted to the main body 26 instead. Preferably in this case, the ACvoltage is applied to the plurality of piezo elements 14 in a mannersuch that the vibrations of the piezo elements 14 are matched in phase.Also, the mounting positions of the piezo elements 14 with respect tothe main body 26 are not restricted to the upper surface of the mainbody 26 and may be at a side surface or other position of the main body26 besides the upper surface. Specifically, all of the piezo elements 14may be mounted to a side surface of the main body 26. Also, in a casewhere a plurality of piezo elements 14 are mounted to the main body 26,the piezo elements 14 may be mounted to the upper surface and a sidesurface of the main body 26.

Also, although with each of the first and second embodiments, a casewhere the locus X1 is a curve has been described, the locus X1 may be astraight line instead. That is, the locus X1 may be a straight line thatextends along the upper surface of the substrate W held by the spinchuck 2 and passes through the center C1 of the upper surface of thesubstrate W when viewed from the perpendicular direction perpendicularto the upper surface of the substrate W.

Also, although with the first or second embodiment, a case where thesubstrate processing apparatus 1 or 201 is an apparatus that processes acircular substrate, such as a semiconductor wafer, etc., has beendescribed, the substrate processing apparatus 1 or 201 may be anapparatus that processes a polygonal substrate, such as a glasssubstrate for liquid crystal display device.

Further, with the second embodiment, in the state where the spray nozzle4 is positioned at the central position Pc201, the spray nozzle 4 isheld by the nozzle arm 18 in a manner such that the two columns L1corresponding to the middle portion 39 positioned at the peripheral edgeposition Pe201 side are orthogonal to the tangential line of the locusX1 at the center C1. However, it suffices that the spray nozzle 4 beheld in a manner such that the four columns L1 intersect the locus X1,and, for example, the spray nozzle 4 may be held by the nozzle arm 18 ina manner such that two columns L1 are oblique with respect to the radiusR1 of the substrate W.

Although the embodiments of the present invention have been described indetail, these embodiments are merely specific examples used to clarifythe technical contents of the present invention, and the presentinvention should not be understood as being limited to these specificexamples, and the scope of the present invention are limited solely bythe appended claims.

The present application corresponds to Japanese Patent Application No.2011-044375 filed in the Japan Patent Office on Mar. 1, 2011 andJapanese Patent Application No. 2011-075660 filed in the Japan PatentOffice on Mar. 30, 2011, and the entire disclosures of theseapplications are incorporated herein by reference.

1. A nozzle arranged to discharge droplets of a processing liquid forprocessing a substrate, the nozzle comprising: a main body; and a piezoelement; the main body including: a supply port supplied with theprocessing liquid; a drain port from which the processing liquidsupplied to the supply port is drained; a processing liquid flowpassageway connecting the supply port and the drain port, the processingliquid flow passageway including a plurality of branch flow channelsbranching out between the supply port and the drain port and collectingtogether between the supply port and the drain port; and a plurality ofdischarge ports forming a plurality of columns respectivelycorresponding to the plurality of branch flow channels, being alignedalong the corresponding branch flow channels, and being connected to thecorresponding branch flow channels; the piezo element arranged to applyvibration to the processing liquid flowing through the plurality ofbranch flow channels.
 2. The nozzle according to claim 1, wherein themain body is formed of a material containing quartz.
 3. The nozzleaccording to claim 1, further comprising: a wiring connected to thepiezo element; and a cover covering a both the piezo element and thewiring therewithin.
 4. The nozzle according to claim 1, wherein the mainbody further includes: connection channels connecting the branch flowchannels and the discharge ports; and each of the connection channelsincludes: a reduced portion that reduces in flow path area as thedischarge port is approached.
 5. The nozzle according to claim 4,wherein the processing liquid flow passageway and the connectionchannels are arranged in an interior of the main body, and the main bodyincludes a plurality of divided bodies that are joined to each other. 6.A substrate processing apparatus comprising: a substrate holding unitarranged to hold a substrate; a nozzle arranged to discharge droplets ofa processing liquid toward the substrate held by the substrate holdingunit; a processing liquid supply unit arranged to supply the processingliquid to a supply port of the nozzle; and a voltage applying unitarranged to apply voltage to a piezo element of the nozzle; the nozzleincluding: a main body and the piezo element; the main body including:the supply port supplied with the processing liquid; a drain port fromwhich the processing liquid supplied to the supply port is drained; aprocessing liquid flow passageway connecting the supply port and thedrain port, the processing liquid flow passageway including a pluralityof branch flow channels branching out between the supply port and thedrain port and collecting together between the supply port and the drainport; and a plurality of discharge ports forming a plurality of columnsrespectively corresponding to the plurality of branch flow channels,being aligned along the corresponding branch flow channels, and beingconnected to the corresponding branch flow channels; the piezo elementarranged to apply vibration to the processing liquid flowing through theplurality of branch flow channels.
 7. The substrate processing apparatusaccording to claim 6, further comprising a nozzle moving unit beingarranged to move the nozzle along a locus, wherein the locus extendsalong a major surface of the substrate held by the substrate holdingunit and passes through a center of the major surface when viewed from aperpendicular direction perpendicular to the major surface, and holdingthe nozzle so that the plurality of columns formed by the plurality ofdischarge ports intersect the locus when viewed from the perpendiculardirection.
 8. The substrate processing apparatus according to claim 7,further comprising a control unit arranged to control the nozzle movingunit to move the nozzle along the locus so that, between a centralposition at which the nozzle overlaps with the center of the majorsurface when viewed from the perpendicular direction and a peripheraledge position at which the nozzle overlaps with a peripheral edge of themajor surface when viewed from the perpendicular direction, theplurality of columns overlap successively with the center of the majorsurface when viewed from the perpendicular direction.
 9. (canceled) 10.A substrate processing apparatus comprising: a substrate holding androtating unit that is arranged to hold and rotate a substrate; a nozzlehaving disposed therein a plurality of columns, in each of which aplurality of discharge ports discharging droplets of a processing liquidare aligned in a single column, and arranged to discharge the dropletsof the processing liquid toward the substrate held by the substrateholding and rotating unit; and a nozzle holding and moving unit beingarranged to move the nozzle along a locus, wherein the locus passesthrough a rotation center of a major surface of the substrate held bythe substrate holding and rotating unit when viewed from a perpendiculardirection perpendicular to the major surface, and being arranged to holdthe nozzle so that the plurality of columns intersect the locus whenviewed from the perpendicular direction.
 11. The substrate processingapparatus according to claim 10, further comprising; a control unitarranged to control the nozzle holding and moving unit to move thenozzle along the locus so that, between a central position at which thenozzle overlaps with the rotation center of the major surface whenviewed from the perpendicular direction and a peripheral edge positionat which the nozzle overlaps with a peripheral edge of the major surfacewhen viewed from the perpendicular direction, the plurality of columnsoverlap successively with the rotation center of the major surface whenviewed from the perpendicular direction.
 12. The substrate processingapparatus according to claim 10, wherein the nozzle includes: a mainbody having processing liquid flow channels, which are connected to thedischarge ports and in which the processing liquid flows through alongthe columns, provided in respective correspondence to each of theplurality of columns; and a piezo element arranged to apply vibration tothe processing liquid flowing through the processing liquid flowchannels; and the substrate processing apparatus further comprises: avoltage applying unit that is arranged to apply voltage to the piezoelement. 13-14. (canceled)